Cables with bonded organic filamentary insulation



Ag. 9, 1966 G. MORIERAS CABLES WITH BONDED ORGANIC FLAMENTARY INSULATlON Filed Jan. 20, 1964 N VE N VOIR 6' Nye/ Maneras' ATTORNEYS United States Patent() r'ce 6 Claims. (l. 174--'-121) The present invention relates to new products, cables and similar articles, and a process for producing them.

It is known to produce cables consisting of an elementary core and an external envelope. The core yarns may be characterised by the absence of appreciable twist, these yarns being assembled with one another land with the external envelope surrounding them by means of an appropriate chemical binder. These ropes have a particularly high breaking strength with lowelongation.

The presentnvention provides a cable comprising at least one substantially axial liliform metallic element'surrounded by a composite structure consisting of textile yarns substantially parallel to the laxial element and at least one external envelope united to the yarns, the filiform element possessing different dynamometric characteristics from the composite structure.

In a preferred cable, the axial element has an elongation at break, which is greater than that of the 4composite structure. i

The nature of the'cable may be varied to suit any par- I ticular use by appropriate choice of the constituent elements. 'It is possible to use stranded or unstranded electric conductors as the axialelement. Such cables possess a distinctly lower weight than conventional electric cables, and they are consequently easier to handle. Thenature of the composite element may be so chosen that the cables are insensitive to water, to weather inuences and to cold,`

and have good resistance to extem'al. corrosive agents, while requiring no maintenance during service.

The axial element may also have a breaking load which is higher then the maximum working load tolerated by the composite structure. Any strong and non-inllammable material which conforms to this definition, such as steel rope, may be employed so that the cable will not suddenlybreak under load, for example. in the event of accidental wear.

A preferred embodiment of the present `invention will t nowbe described with reference to the accompanying drawing in which the axial element has been labeled as a The axial element, when the cable is to metal element. be used as an electrical` conductor, can comprise a metal wire coated with a suitable electrical insu-lation. 'Phe axial element is surrounded by a plurality of .continuous filaments which are parallel to the axial element. The filaments-are bonded together and the assembly is covered with a suitable envelope.

Any known method may be employed to produce such cables but the lfollowing method is preferred. The textile yarns are impregnated with a chemical binder, the axial element and the textile yarns are assembled continuously and at least one envelope is then applied while the binder is still in the adhesive state, the envelope being impregnated at least partially due to the exudation of the binder when it is united with the textile yarns.

In a preferred embodiment ofv the present invention, the textile yarns are introduced parallel to one another, in the formof a sheet, into a bath containing an appropriate chemical binder, togetherwith an axial element which is optionally coated or sheathed. By means of a device,

such as a perforated disc, the yarns are uniformly distributed in circular arrangement around the axial element, the binder is partially dried and the assembly is Patented August 9, 1966 thereafter united without twisting. An external envelope obtained, for example. by braiding is deposited on this assembly, optionally after rte-impregnation. The braid is Aimpregnated by the binder which exudes through it and this may be supplemented by continuous' passage through a second binder bath which thus completes the protection ofthe assembly.

The textile yarns employed for the formation of these cables may be of natural, artificial or, preferably, synthetic origin, the latter types of yarns having the advantage of higher strength for a given weight. Suc-h yarns are, notably, based on polyamide, polyester. polyoletine, polyacryl, polyvinyl, etc. Advantageously, yarns having very high strength and low elongation will be employed, which under these conditions retain their mechanical properties to the maximum extent.

The binders employed for the impregnation of the textile filaments may be of very varied nature: natural or synthetic Velastomers, in the form of a latex or a solution, vinyl `or other polymers, polycondensatcs, parnliins, waxes, etc., and they advantageously contain protecting and/or stabilising agents. Depending upon thc nature of the bindeigythe latter may be deposited in solution. in dispersion or in a viscous `liquid state.

Some binders, such as elastomers, may be self-curing or they may be subjected to curing after the cable has been formed. ln order to render these cables incombustible and/or imputrescible, it is sutlicient to incorporate tire- :prooling and/or fungcidal products in thebinder.

The external envelope may be obtained by lapping, taping, extrusion or, preferably, braiding and may be 'applied continuously. If desired, vit may be externally coated with an abrasion-resistant resin, such as polyvinyl chloride, synthetic elastomers, polyamides, polyt'etralluoroethylenes, etc.

In order that the technical features and the advantages ofthe present invention may be more readily understood, two embodiments thereof will be described by way of example.

Example I 170 high-tenacity polyethylene terephthalate yarns having a count of i000 deniers/200 ilaments, and a bare copper cord having a diameter of 3 mm. and composed of 7 elemental lilaments having n diameter ot` l mm., are passed parallel to one another, in sheet form,through a binder consisting of a self-curing enriched rubber latex containing fungicidcs and curing ingredients. On leaving the tank, the yarns are carried vertically upwards, wherealterthey are passed through a perforated disc which positions them in relation to one another, so that the axial element is located at the centre ofthe said disc. At the same time, drying of the binder is commenced.

The assembly, consisting of the yarns and the copper cord, is passed through a calibrating nozzle, the oriliee of which has a diameter similar to the final diameter of t-he cord. The assembly thus shaped and still impregnated with fresh binder is passed along the axis of a braiding machine comprising i6 spindles each supplying 3 yarns of polyethylene tercphthalate having a count of 1000 deniers/200 lilamcnts.

The assembly' is thereafter passed through a self-curing I-lypalon solution charged with carbon black, and then through a resilient conical sleeve, of which the smallest diameter corresponds substantially to the diameter of the finished cable, the surface of the latlcr thus being smoothed.

The product is thereafter passed through a tunnel oven, of which the temperature varios between 50 and 130 C. and in which it remains for about 5 minutes, whereby drying ol the binder :md its curing arc ensured.

Such a cable is designated A in the following table, a

Diameter Weight. in Breaking Elougntion in mm. g./m. load in kg. at; hrvuk,

percent.

Example II The same procedure is adopted as in Example l but the copper cord is replaced by a steel rope having the following characteristics:

Diameter in mm. 1.4 Weight in g./m v12 Breaking load in kg. 205

rThis steel rope is surrounded by a textile`complex formed of 100 elemental high-tenacity polyethylene terephthalate yarns, 1000 deniers/200 laments, having a 20 S twist, and by a braided envelope obtained from 16 spindles fed with polyhexamethylene adipamide yarns, 840 deniers/3 filaments, having a 70 Z twist.

The cord obtained weighs 33 grams per metre and works undernormal conditions with loads below 200 kg. If, in this zone of use, an accident occurs which results in breakage of the composite element, such asl shearing, wear due to alternating forces, tire, etc., the steel rope supports the -load momentarily yand thus increases the safety of such cables in use.

This type of cable is also suitable for static uses, such as cables for avalanche barriers.

I claim:

1. A cable comprising at least one substantially axial lform metallic element surrounded by a composite textile structure consisting of a bundle of organic continuous filament yarns substantially parallel to the axial metallic element and by at least one external braided envelope, said composite textile structure being impregnated by an organic bonding material,` the axial metallic clement having one dynamometric property selected from the group which consists of maximum working load and elongation at break greater than that of the remainder of. the composite structure of the cable.

2. A cab-le according to claim l in which thcaxal metallic element is an electric conductor.

3. A cable according to claim l, in which the axial metallic element is of copper and has an elongation at break greater than that of the remainder ot the composite structure of the cable. l

4. A cable according to claim 1 in which the axial lmetallic element is a load bearing element.

5. A cable according to claim 1 in which the axial metallic element is of steel and has a maximum working load greater than that of the remainder of the compositev structure of the cable. 6. A cable according to claim 1 in which the bonding material is a cured elastomer.

References Cited by the Examiner UNITED STATES PATENTS LEWIS H. MYERS, Primary Examiner.

JOHN F. BURNS, Examiner. D. A. KETTLESTRINGS', A ssismnt Examiner. 

1. A CABLE COMPRISING AT LEAST ONE SUBSTANTIALLY AXIAL FILIFORM METALLIC ELEMENT SURROUNDED BY A COMPOSITE TEXTILE STRUCTURE CONSISTING OF A BUNDLE OF ORGANIC CONTINUOUS FILAMENT YARNS SUBSTANTIALLY PARALLEL TO THE AXIAL METALLIC ELEMENT AND BY AT LEAST ONE EXTERNAL BRAIDED ENVELOPE, SAID COMPOSITE TEXTILE STRUCTURE BEING IMPREGNATED BY AN ORGANIC BONDING MATERIAL, THE AXIAL METALLIC ELEMENT HAVING ONE DYNAMOMETRIC PROPERTY SELECTED FROM THE GROUP WHICH CONSISTS OF MAXIMUM WORKING LOAD AND ELONGATION AT BREAK GREATER THAN THAT OF THE REMAINDER OF THE COMPOSITE STRUCTURE OF THE CABLE. 